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Fishery Bulletin 105(3) 



Results 



Hydrography 



The water column at the sampling station was simi- 

 larly stratified for each of the nine diel hauls, and a 

 thermocline was centered approximately at 20 m (Fig. 

 1, A and B). Mean water temperature was 14.7°C (stan- 

 dard deviation [SD]=1.6) at the surface, and decreased 

 to 6.2°C (SD = 0.2) at 350 m. Salinity increased from 

 a mean of 31.9 psu (SD = 0.7) at the surface to 34.0 

 psu (SD = 0.03) at 350 m. The unusually low salinities 

 recorded in the upper 35 m of the water column during 

 the last haul in 2000 (HH-05G1 may have resulted from 

 an infusion of low-salinity Columbia River plume water 

 from the north. 



Egg concentrations and distributions 



A surprisingly small sum of 128 fish eggs representing 

 11 taxa from nine families was collected throughout 

 the study. Three taxa were dominant according to 

 total mean concentration and frequency of occurrence 

 from all depth-stratified samples: S. sagax (3.42/1000 

 m3; 0.07), /. lockingtoni (2.00/1000 m^; 0.14), and C. 

 macouni (1.07/1000 m^; 0.12). Together these three 

 taxa accounted for over 71% of the total mean egg 

 concentration. Trachurus symmetricus (jack mackerel) 

 eggs were found at a high concentration (241.29/1000 

 m^) in a single daytime surface (0-10 m) sample in 

 2000 but were found in only two other samples and 

 at much lower densities (6.80 and 17.54/1000 m^). 

 These two samples were collected from two depths 



